Method of packaging electrical connectors and assembling same into a wire wrap machine

ABSTRACT

Described is a method of packaging a number of electrical connectors for use with an automatic wire-wrapping machine and described also is a frame for supporting the connectors. The method comprises providing a jig having a master reference pin and located therefrom a number of paired alignment pins. Moldedin alignment holes on the connectors mate with the paired alignment pins when the connectors are mounted upon the jig. A frame having a rectangular opening fits about the positioned connectors while oversized pair alignment openings in the frame are adapted to receive machine screws which are then threaded in mating holes in the connectors. The frame also has a second hole for mounting over the master reference pin which corresponds to a master reference pin on the automatic wire-wrapping machine. The wrapping machine receives the frame-connector package after the frame is separated from the jig.

United States Patent Scaminaci, Jr. et al.

[ Feb. 15,1972

[72] Inventors: James Scaminaci, Jr., Newbury Park, Calif; Robert G.Knowles, Litchfield,

Conn.

[73] Assignee: Litton Systems, Inc., Beverly Hills, Calif.

[22] Filed: Sept. 18, 1968 [21] Appl.No.: 760,499

[52] US. Cl. ..29/629, 29/203 R, 29/464 R, 29/469 R, 29/624 R, 140/71 C,242/7.l7 R, 242/7.18 R, 269/47 R 2,347,411 5/1944 Hefler et al.....29/464 2,934,590 4/1960 Thompson et al. ....174/53 3,088,728 5/1963Sanbom ..29/203 J 3,266,125 8/1966 Tobolski ..29/627 3,323,023 5/1967Walker ..29/626 3,378,160 4/1968 Bassani ..174/58 X 3,392,256 7/1968Bradham.... .29/203 B X 2,855,159 10/1958 Mallina ..242/7.18 3,451,6336/1969 Markham et al ..242/7. 1 8

Primary Examiner-John F. Campbell Assistant Examiner-Robert W. Church At!0rneyAlan C. Rose, Ronald W. Reagin, Joseph H. Golant and Alfred B.Levine 5 7] ABSTRACT Described is a method of packaging a number ofelectrical connectors for use with an automatic wire-wrapping machineand described also is a frame for supporting the connectors. The methodcomprises providing a jig having a master reference pin and locatedtherefrom a number of paired alignment pins. Molded-in alignment holeson the connectors mate with the paired alignment pins when theconnectors are mounted upon the jig. A frame having a rectangularopening fits about the positioned connectors while oversized pairalignment openings in the frame are adapted to receive machine screwswhich are then threaded in mating holes in the connectors. The framealso has a second hole for mounting over the master reference pin whichcorresponds to a master reference pin on the automatic wire-wrappingmachine. The wrapping machine receives the frame-connector package afterthe frame is separated from the jig.

1 Claims, 4 Drawing Figures BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates to a method of packaging electricalconnectors and to a frame for the electrical connectors and moreparticularly to a method of precisely locating and packaging electricalconnectors and to a frame for supporting the connectors during automaticwiring operations.

2. Description of the Prior Art In 1958 the Gardner-Denver Company ofGrand Rapids, Michigan introduced a punchcard controlled machine thatwould automatically strip insulation from a solid wire, properly routeit on a wiring panel, and then wrap it around the desired terminal postof an electrical connector thereby effecting a solderless wrapinterconnection quickly and inexpensively. The Gardner-Denver automaticwire-wrapping machine has the capability of terminating over 500 wiresan hour, thereby reducing wire terminating costs by more than 400percent over the older manual method of wire-wrapping. In thewire-wrapping process the bare end of an insulated wire is wrapped abouta terminal post having sharp corners. Since the wrapping is done undertension, the wire and the terminal post are deformed at the point ofcontact, i.e., the corners. Thus the wrapped wire is held to the post bythe stresses left in the wire and the post. The average pressure betweenthe wire and the post is 30,000 p.s.i.; this pressure is more thansufficient to meet the requirements of a gastight connection. With theadvent of the automatic wire-wrapping machine however, came stringentrequirements for the position in the X- Y plane of connector terminalposts. The posts must be positioned within a circle of radius 0.010 inch(or a circle with diameter 0.020 inch) centered at the true position.

The prior art is replete with examples of various schemes for exactlylocating terminal posts in an effort to take advantage of theexpediencies offered by the automatic wire-wrapping machine. An earlyscheme required a precision punched metal screen into which individualterminal posts were placed and then straightened. This scheme wasexpensive because the screen was difficult to precision manufacture dueto metal growth during the punching process and screen rolling orbending as each row was punched. Secondly, placement of individualterminal posts was time consuming as well as expensive and required theadditional process step of press fitting nylon bushings into the punchedscreen and then the placement in the bushing of the terminal post.Finally, each row of terminal posts must then be straightened, requiringstill another process step and added expense.

An improvement scheme comprised providing a quad block, that is, a smallblock into which four terminal posts were inserted. The four pins of thequad block were then pressed into four corresponding openings in theprecision punched screen. Still a further improvement on the precisionpunched screen approach was the placement of a plurality of posts in aflexible connector block which were then fitted into the correspondingopenings in a screen. However, all of the above schemes still requiredthe precision punched metal screen with its inherent disadvantages andexpensive processing costs.

As the industry moved toward the rigid electrical connector block wherethe terminals were located in a solid plastic base so as to give theterminal posts structural integrity, various schemes were developed toobviate the need of the precision punched metal screen. One such systemdeveloped a plate in which larger openings the size of the connectorblock-were punched with extremely close tolerances being required at theend of the rectangular punched opening to correctly position theconnector. Such plates were still expensive to manufacture andadditionally required that the electrical connector have closetolerances since the electrical connector became the major positioningbody. Still another technique was the replacement of the precisionpunched metal screen by a printed circuit board having a plurality ofopenings to correspond to each of the terminal posts in a connector orseries of connectors. This scheme, while easier to keep tolerancesbecause of the inherent advantage of a printed circuit boardtype screenover the precision punched metal screen, still required an expensivemanufacturing process and still required the straightening of theterminal posts once relatively positioned by the printed circuit board.

SUMMARY OF THE INVENTION All of the above disadvantages have beenalleviated by the present invention which provides a method of packagingelectrical connectors for wire-wrapping comprising the steps ofproviding a means for positioning the electrical connector relative to amaster reference location, locating the electrical connector accordingto the positioning means, providing a means for supporting theelectrical connector, the supporting means having means for enabling theelectricalconnector to be attached to the supporting means and attachingthe electrical connector to the supporting means as positioned by thepositioning means. A preferred embodiment of the means for supportingelectrical connectors comprises a plate having at least one opening forreceiving the connectors, the plate having paired apertures disposed onopposite sides of the opening for receiving screws which mate withthreaded apertures in the connectors and the plate having a secondopening spaced from the first mentioned opening for receiving a masterreference pin for precisely locating the plate.

An object of the present invention is to provide a method of accuratelyaligning terminal posts quickly and inexpensively with a relatively lowrate of misalignment rejection.

Another object of the present invention is to provide a method ofaligning terminal posts so as to minimize the downtime of an automaticwire-wrapping machine.

A further object of the present invention is to provide a supportingmeans or frame for electrical conductors which is simple, easilymanufactured and inexpensive, and which allows for accurate placement ofthe terminal posts of the electrical connectors.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of aprecision jig upon which are mounted a number of electrical connectors.

FIG. 2 is a perspective view of a supporting means mounted upon theprecision jig shown in FIG. 1 with the electrical connectors partiallyconnected to the supporting means.

FIG. 3 is a side view of the supporting means with the connectedconnectors after the supporting means has been separated from theprecision jig.

FIG. 4 is a plan view of an electrical connector.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingwherein like referenced numerals designate like or corresponding partsthroughout the several views, there is shown in FIG. 1 a precision jigl0 having a number of electrical connectors 12 mounted thereto. Anelectrical connector comprises a molded body 14 which may be ofglass-filled diallyl phthalate having a predetermined number of anchoredterminal posts 16 which are to receive the wire wrap. The terminal posts16 are of homogeneous drawn, high-tensile phosphor bronze wire having an0.025 inch square cross section. Each connector has two cars 18 whichmay be molded integral with the body 14, each ear having a threaded hole20 which is adapted to receive a machine screw. A more detaileddescription of the electrical connector is given in a copendingapplication, Ser. No. 760,561 titled Electrical Connector With TwistedPosts assigned to the assignee of the present invention.

The ends 22 of the terminal posts 16 require the critical positioningwithin the above-mentioned 0.020 diameter circle so as to be operablewith the automatic wire-wrapping machine. Within a surface 23, FIG. 4,oppositely disposed from a surface 24, FIG. I of the body 14 from whichthe terminal posts 16 extend, is a longitudinal cavity 25 which isadapted to receive the terminal end ofa printed circuit board (notshown). The ends 27 of the terminal posts 16 opposite ends 22 arebifurcated and are disposed along the periphery of the longitudinalcavity 25 so as to make contact with the circuitry ofthe printed circuitboard.

The jig comprises a flat plate 26 into which is positioned a masterreference pin 28. The master reference pin 28 corresponds to ananalogous pin located on the automatic wirewrapping machine and is usedto measure distances and locations for the arms of the automaticwire-wrapping machine. For convenience a second pin 30 is located on theplate 26 to act as a guide for a supporting means as explainedhereinafter.

Accurately positioned on the plate 26 is a series of paired positioningor alignment pins 32. Each pin is independently measured from the masterreference pin 28 and each is within 0.00I inch of true position. Of eachpair of pins 32, one has a circular cross section while the other has aflattened circular cross section (that is, having a configuration whichis a portion of a circle with two parallel chords forming a part of theperiphery). The pairs of pins 32 cooperate with molded-in alignmentopenings 29 and 31, FIG. 4 in the body 14 so as to accurately locateeach of the connectors relative the master reference pin 28. In turneach of the terminal posts 16 is precisely located from the twoalignment openings 29 and 31 so that the terminal posts 16 are in exactposition relative the master reference pin 28.

To insure that the ends 22 of the terminal posts are precisely locatedthe posts are straightened during the same operation that twists theposts for anchoring them in the base 14. For more detail of the twistingand straightening operation reference is made to copending application,Ser. No. 760,404 titled DEVICE FOR TWISTING AND ALIGNING TER- MIN ALPOSTS OF AN ELECTRICAL CONNECTOR assigned to the assignee of the presentapplication. The combination ofa round pin and a round flattened pinprovides for an exactly located electrical connector which is rigidlyretained in the direction of the Y-axis and allowed a slight movement inthe direction of the X-axis to compensate for mold shrinkage oftheplastic body 14.

Referring now to FIG. 2 there is shown the plate 26 with the mountedelectrical connectors 12 as shown in FIG. 1. In addition, mounted uponplate 26 is a supporting means 40 for the electrical connectors Thesupporting means 40 comprises a frame plate 41 having two rectangularopenings 42 which allow the terminals posts 16 of the electricalconnector 12 to protrude so as to receive wire wrapping. Disposed onopposite sides of each of the rectangular openings 42 are a series ofpaired alignment apertures 44 corresponding to the holes in the ears 18of the electrical connectors 12. Hence, by inserting a machine screw 46,more clearly shown in FIG. 3, into the aperture and threading it intothe hole 20 of the electrical connector, the electrical connectorbecomes attached to the supporting means. It is to be noted that thepaired alignment apertures 44 are made oversize, that is, having alarger diameter than the shank of the machine screw 46 so that theposition of the electrical connectors in relation to the supportingmeans 40 is determined by the alignment pins 32 on the precision jig 10.

In addition to the openings 42 and the paired alignment apertures 44 thesupporting means 40 has a second set of openings 48 and 50 which arediagonally disposed across the supporting means. These openings 48 and50 correspond to the master reference pin 28 and pin 30 for preciselylocating the supporting means relative the jig. It is recalled themaster reference pin 28 corresponds to an analogous reference locationon the automatic wire-wrapping machine so that after the electricalconnectors are spaced and positioned correctly and attached to thesupporting means, the supporting means may be removed from the jig 10(FIG. 3 illustrates the supporting member 40 with the attachedelectrical connectors 12) and may then be directly transferred to theautomatic wirewrapping machine with the terminal posts 16 having theirends 22 in the proper X-Y alignment as required by the automaticwire-wrapping machine.

It is to be understood that the geometry of the jig l0 and supportingmeans 40 as shown is an example only and that the jig plate 26 may takea variety of geometric configurations depending upon the required designlocations of the electrical connectors. It is also to be understood thatthe electrical connectors may be placed in any combination in a varietyof differently shaped openings in the supporting means as required bythe stack with which the electrical connectors will be mated. Forexample, as viewed in FIG. 1 the left side ofthe jig has six electricalconnectors mounted in a row immediately adjacent to each other in arectangular opening while the right side has one electrical connectorspaced from two immediately adjacent electrical connectors. The openingsin the frame plate 41 could be made square or two smaller openings couldbe formed or the plate could be extended and a third opening addedFurther, it is noted that in FIG. 2 there is room for more electricalconnectors to be added if such may become necessary at a later date orif the design configuration of the mating stack is changed.

The first step in packaging the electrical connector is providing ameans for positioning the electrical connectors relative to a masterreference location; in the preferred embodiment this takes the form ofthe jig 10 with master reference pin 28 and the paired alignment pins32. The next step is that of locating the electrical connectorsaccording to the positioning means which entails mounting the electricalconnectors 12 using the alignment openings 29 and 31 in the connector tothe pair of alignment pins 32. The next step is that of providing ameans for supporting the electrical connectors with the supporting meanshaving means for enabling the electrical connector to be attached to thesupporting means. In the preferred embodiment the supporting means 40has the aired apertures 44 which are adapted to receive machine screwsfor threadedly engaging the electrical connectors. The last step is thatof attaching the electrical connectors to the supporting means aspositioned by the positioning means. This is accomplished by using themachine screws to attach the electrical connectors 12 to the supportingmeans 40; since the paired apertures 44 are oversized, location of themachine screws 46 is determined by alignment ofthe electrical connectorswhich in turn is determined by the paired alignment pins 32 on thejig10.

Once the electrical connectors are attached to the supporting means, thesupporting means is separated from the jib by a parallel lift-off andtransferred to the automatic wire-wrapping machine.

Once again it is to be understood that various changes can be made tothe elements as shown in FIGS. 1, 2, 3 and 4 without departing from thespirit and scope of the present invention.

As an example, the paired alignment pins 32 on the jig 10 may bereplaced by a series of parallel ribs which would fit into thelongitudinal cavity 25, FIG. 4 in each of the connectors and thereby actas a precise positioning means. Likewise the alignment pins 32 may beused and be located to fit in the extreme ends of the longitudinalcavity to act as a positioning means. Or, still another derivation maybe accomplished by having the alignment pins fit within the openings 20in each of the cars 18 of the connector to act as a positioning means.Similarly the master reference pin 28 may be replaced by anothersuitable reference device with an analogous device being used on theautomatic wire-wrapping machine. Finally, the means of attaching theelectrical connectors to the supporting means may be by a suitable cliprather than the disclosed machine screws.

We claim:

1. A method of packaging electrical connectors for use within awire-wrapping machine wherein said connectors are characterized ashaving alignment apertures therein comprising the steps of:

frame wherein said attached connectors are aligned with said alignmentlocation on said support frame;

removing said support frame and said aligned connectors attachedthereto;

placing said support frame and said aligned connectors attached theretoin said wire-wrapping machine; and

aligning said alignment location on said support frame with a referenceposition within said wire-wrapping machine for aligning said connectorswith said wire-wrapping machine.

1. A method of packaging electrical connectors for use within awire-wrapping machine wherein said connectors are characterized ashaving alignment apertures therein comprising the steps of: placing saidelectrical connectors on an alignment jig having a master referencelocation thereon and alignment pins aligned therefrom. aligning thealignment apertures within said connectors with said alignment pins foraligning said connectors with said master reference location; placing asupport frame having an alignment location thereon in contact with saidaligned connectors on said alignment jig; aligning said alignmentlocation on said support frame with said master reference location onsaid alignment jig; attaching said aligned connectors to said alignedsupport frame wherein said attached connectors are aligned with saidalignment location on said support frame; removing said support frameand said aligned connectors attached thereto; placing said support frameand said aligned connectors attached thereto in said wire-wrappingmachine; and aligning said alignment location on said support frame witha reference position within said wire-wrapping machine for aligning saidconnectors with said wire-wrapping machine.